//
//  strings.c
//  CloverX64
//
//  Created by Jief on 01/02/2021.
//

#include "strings.h"


/*
 * This array is designed for mapping upper and lower case letter
 * together for a case independent comparison.  The mappings are
 * based upon ascii character sequences.
 */
static const unsigned char charmap[] = {
        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
        0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
        0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
        0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
        0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
        0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
        0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
        0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
        0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
        0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
        0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
        0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
        0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
        0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
        0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
        0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
        0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
        0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
        0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
        0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
        0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
        0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
        0xc0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
        0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
        0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
        0xf8, 0xf9, 0xfa, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
        0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
        0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
        0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
        0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
};

int strncasecmp(const char* s1, const char* s2, size_t n)
{
    unsigned char u1, u2;
    for (; n != 0; --n) {
        u1 = (unsigned char) *s1++;
        u2 = (unsigned char) *s2++;
        if (charmap[u1] != charmap[u2]) {
            return charmap[u1] - charmap[u2];
        }
        if (u1 == '\0') {
            return 0;
        }
    }
    return 0;
}

int strcasecmp(const char* s1, const char* s2)
{
    unsigned char u1, u2;
    for (;;) {
        u1 = (unsigned char) *s1++;
        u2 = (unsigned char) *s2++;
        if (charmap[u1] != charmap[u2]) {
            return charmap[u1] - charmap[u2];
        }
        if (u1 == '\0') {
            return 0;
        }
    }
}
